President Barack Obama isn’t saying just when he learned about the reported U.S. eavesdropping on leaders of U.S. allies.

But in a TV interview, Obama said the government is conducting a “complete review” of how U.S. intelligence operates elsewhere. He wouldn’t discuss specifics in the interview on the new TV network Fusion.

A senior administration official has said the White House is considering an end to the practice of listening in on friendly foreign leaders.